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Flynn's taxonomy | Multiple instruction streams, multiple data streams (MIMD) | Multiple instruction streams, multiple data streams (MIMD)
Multiple autonomous processors simultaneously execute different instructions on different data. MIMD architectures include multi-core superscalar processors, and distributed systems, using either one shared memory space or a distributed memory space. |
Flynn's taxonomy | Diagram comparing classifications | Diagram comparing classifications
These four architectures are shown below visually. Each processing unit (PU) is shown for a uni-core or multi-core computer: |
Flynn's taxonomy | Further divisions | Further divisions
, all of the top 10 and most of the TOP500 supercomputers are based on a MIMD architecture.
Although these are not part of Flynn's work, some further divide the MIMD category into the two categories below, and even further subdivisions are sometimes considered. |
Flynn's taxonomy | Single program, multiple data streams (SPMD) | Single program, multiple data streams (SPMD)
Multiple autonomous processors simultaneously executing the same program (but at independent points, rather than in the lockstep that SIMD imposes) on different data. Also termed single process, multiple data - the use of this terminology for SPMD is technically incorrect, as SPMD is a parallel execution model and assumes multiple cooperating processors executing a program. SPMD is the most common style of explicit parallel programming. The SPMD model and the term was proposed by Frederica Darema of the RP3 team. |
Flynn's taxonomy | Multiple programs, multiple data streams (MPMD)<!--'' redirects here--> | Multiple programs, multiple data streams (MPMD)
Multiple autonomous processors simultaneously operating at least two independent programs. In HPC contexts, such systems often pick one node to be the "host" ("the explicit host/node programming model") or "manager" (the "Manager/Worker" strategy), which runs one program that farms out data to all the other nodes which all run a second program. Those other nodes then return their results directly to the manager. An example of this would be the Sony PlayStation 3 game console, with its SPU/PPU processor.
MPMD is common in non-HPC contexts. For example, the make build system can build multiple dependencies in parallel, using target-dependent programs in addition to the make executable itself. MPMD also often takes the form of pipelines. A simple Unix shell command like ls | grep "A" | more launches three processes running separate programs in parallel with the output of one used as the input to the next.
These are both distinct from the explicit parallel programming used in HPC in that the individual programs are generic building blocks rather than implementing part of a specific parallel algorithm. In the pipelining approach, the amount of available parallelism does not increase with the size of the data set. |
Flynn's taxonomy | See also | See also
Feng's classification
Duncan's taxonomy
Händler's (ECS) |
Flynn's taxonomy | References | References
Flynn's taxonomy |
Flynn's taxonomy | Table of Content | short description, Classifications, Single instruction stream, single data stream (SISD), Single instruction stream, multiple data streams (SIMD), Array processor, Pipelined processor, Associative processor, Multiple instruction streams, single data stream (MISD), Multiple instruction streams, multiple data streams (MIMD), Diagram comparing classifications, Further divisions, Single program, multiple data streams (SPMD), Multiple programs, multiple data streams (MPMD)<!--'' redirects here-->, See also, References |
1799 in literature | Short description |
This article contains information about the literary events and publications of 1799. |
1799 in literature | Events | Events
thumb|350px|Dove Cottage
Premières of the second and third parts of Friedrich Schiller's dramatic trilogy Wallenstein are performed at the Weimarer Hoftheater under Johann Wolfgang von Goethe:
January 30 – Die Piccolomini.
April 20 – Wallensteins Tod (Wallenstein's Death) as Wallenstein.
April 13 – The father of Charles and Mary Lamb dies; Charles becomes his sister's guardian.
May 8 – The Religious Tract Society is established as an evangelical publisher in Paternoster Row, London; it continues as The Lutterworth Press into the 21st century.
December 20 – William Wordsworth and his sister Dorothy first take up residence at Dove Cottage, Grasmere. William completes the first version of The Prelude during the year.
unknown dates
A new edition of Edward Young's Night Thoughts is illustrated by Thomas Stothard.
The Monthly Magazine and American Review starts publication in the United States, edited by Charles Brockden Brown. |
1799 in literature | New books | New books |
1799 in literature | Fiction | Fiction
Anonymous – Village Orphan
Charles Brockden Brown
Arthur Mervyn
Edgar Huntly
Ormond
Thomas Campbell – The Pleasures of Hope
Elizabeth Gunning – The Gipsey Countess
Mary Hays – The Victim of Prejudice
Friedrich Hölderlin – Hyperion, vol. 2
William Henry Ireland – The Abbess
Jane West – A Tale of the Times
Mary Julia Young – The East Indian |
1799 in literature | Children | Children
François Guillaume Ducray-Duminil – Les Cinquante Francs de Jeannette (Jeanette's Fifty Francs)
Edward Augustus Kendall
The Crested Wren. A Tale
The Canary Bird. A moral fiction interspersed with poetry
Dorothy Kilner (as M. Pelham) – Rational Brutes, or Talking Animals |
1799 in literature | Drama | Drama
Thomas John Dibdin
The Birth Day
Five Thousand a Year
William Dunlap – The Italian Father
Joseph George Holman – The Votary of Wealth
Elizabeth Inchbald – The Wise Man of the East
Kamesuke – Picture Book of the Taiko (kabuki)
Matthew Lewis – The East Indian
Edward Morris – The Secret
Frederick Reynolds – Management
Friedrich von Schiller – Wallensteins Tod
Richard Brinsley Sheridan – Pizarro
Oscar Wegelin – The Natural Daughter
Thomas Sedgwick Whalley – The Castle of Montval |
1799 in literature | Poetry | Poetry |
1799 in literature | Non-fiction | Non-fiction
Hannah Adams – A Summary History of New-England
Hannah More – Strictures on the Modern System of Female Education
Lady Charlotte Murray – The British Garden
Philip Yorke – The Royal Tribes of Wales |
1799 in literature | Births | Births
January 31 – Rodolphe Töpffer, Swiss teacher, author, and artist (died 1846)
February 4
Almeida Garrett, Portuguese writer (died 1854)
Thomas Kibble Hervey, Scottish-born poet and critic (died 1859)
March – Dorothea Tieck, German translator (died 1841)
March 12 – Mary Howitt, English writer, poet and translator (died 1888)
March 13 – Maria Dorothea Dunckel, Swedish poet, translator and dramatist (died 1878)
March 20 – Karl August Nicander, Swedish poet (died 1839)
April 17 – Eliza Acton, English poet and cookery writer (died 1859)
May 13 – Catherine Gore, English author (died 1861)
May 20 – Honoré de Balzac, French novelist (died 1850)
May 23 – Thomas Hood, English poet (died 1845)
June 6 – Aleksandr Pushkin, Russian dramatist and poet (died 1837)
October 9 – Louisa Stuart Costello Irish writer on travel and history (died 1870)
November 29 – Amos Bronson Alcott, American writer, philosopher, and reformer (died 1888)
December 30 – John Moultrie, English poet and hymnist (died 1874)
unknown date – Rallou Karatza, Greek Wallachian translator and theatrical promoter (died 1870) |
1799 in literature | Deaths | Deaths
February 19 – Jean-Charles de Borda, French engineer and memoirist (born 1733)
February 24 – Georg Christoph Lichtenberg, German satirist (born 1742)
April 24 – William Seward, English man of letters (born 1747)
May 18 – Pierre Beaumarchais, French dramatist (born 1732)
August 30 – Eleonora Fonseca Pimentel, Italian poet and revolutionary (executed, born 1751)
December 31 – Jean-François Marmontel, French historian, writer (born 1723) |
1799 in literature | References | References |
1799 in literature | Table of Content | Short description, Events, New books, Fiction, Children, Drama, Poetry, Non-fiction, Births, Deaths, References |
1793 in literature | Short description |
This article contains information about the literary events and publications of 1793. |
1793 in literature | Events | Events
February 7 – The day after poverty-stricken playwright Carlo Goldoni dies, the National Convention votes to restore his French state pension, which has been suspended due to the French Revolution. It is passed on to his widow.
June 1 – In the Reign of Terror in Paris, the Girondist Madame Roland is arrested for treason. She writes Appel à l'impartiale postérité in prison before being guillotined on November 8.
Summer – William Wordsworth tours western England and Wales (passing by Tintern Abbey). His first poems, An Evening Walk and Descriptive Sketches are published this year.
October–November – During the Reign of Terror in the French Revolution, the English writer Helen Maria Williams is imprisoned with her family in the Luxembourg Palace and later in the Convent des Anglaises in Paris, where she continues her translations of French-language works into English, including what will prove to be a popular version of Bernardin St. Pierre's novel Paul et Virginie (1788). To this she appends her own prison sonnets.
November 2 – The French dramatist Olympe de Gouges is sentenced to death by a revolutionary tribunal. Both she and her prosecutors quote the manuscript of her unfinished play La France Sauvée in evidence.
December 9 – New York City's first daily newspaper, the American Minerva, is founded by Noah Webster.
unknown date – James Lackington opens his "Temple of the Muses" bookshop in Finsbury Square, London.
The Royal Library, Denmark, in Copenhagen, opens to the public. |
1793 in literature | New books | New books |
1793 in literature | Fiction | Fiction
Eliza Parsons – The Castle of Wolfenbach
Charlotte Turner Smith
The Old Manor House
The Emigrants
Jane West as 'Prudentia Homespun' – The Advantages of Education, or The History of Maria Williams
Johann Heinrich Daniel Zschokke – Abällino, der grosse Bandit |
1793 in literature | Drama | Drama
Étienne Aignan – La mort de Louis XVI
Elizabeth Inchbald – Everyone Has His Fault
Edward Jerningham – The Siege of Berwick
Jean-Louis Laya – Ami des lois
Edward Morris – False Colours
Arthur Murphy – The Rival Sisters
John O'Keeffe
The London Hermit
The World in a Village
Frederick Reynolds – How to Grow Rich |
1793 in literature | Poetry | Poetry
William Blake
Songs of Experience
Visions of the Daughters of Albion
Alvarenga Peixoto – Canto Genetlíaco |
1793 in literature | Non-fiction | Non-fiction
William Frend – Peace and Union Recommended to the Associated Bodies of Republicans and Anti-Republicans |
1793 in literature | Births | Births
February 2 – Mary Elizabeth Mohl, née Clarke, English-born literary saloniste (died 1883)
April 4 – Casimir Delavigne, French poet and dramatist (died 1843)
May 4 – Dorothea Primrose Campbell, Scottish poet and novelist (died 1863)
June 1 – Henry Francis Lyte, English hymnist and cleric (died 1847)
June 28 – Georg Friedrich Schömann, German classicist (died 1879)
July 2 – Joseph Isidore Samson, French playwright and actor (died 1871)
July 13 – John Clare, English "peasant poet" (died 1864)
July 15 – Almira Hart Lincoln Phelps, American educator, scientist and writer (died 1884)
August 25 – John Neal, American novelist and critic (died 1876)
September 25 – Felicia Hemans, English poet (died 1835)
October 1 – Peter Kaiser, Liechtenstein statesman and historian (died 1864)
November 28 – Carl Jonas Love Almqvist, Swedish novelist (died 1866)
December 15 – Henry Charles Carey, American economist (died 1879)
December 28 – Karl Friedrich Neumann, German Orientalist (died 1870)
unknown date – Sarah Austin, English editor and translator (died 1867) |
1793 in literature | Deaths | Deaths
January 4 – Bengt Lidner, Swedish poet (born 1757)
February 6 – Carlo Goldoni, Italian dramatist and librettist (born 1707)
April 2 – Colin Macfarquhar, Scottish bookseller and printer, co-founder of Encyclopædia Britannica (born c. 1745)
April 29 – John Michell, English philosopher and cleric (born 1724)
May 20 – Charles Bonnet, Swiss naturalist and philosopher (born 1720)
June 26
Gilbert White, English naturalist, diarist and cleric (born 1720)
Karl Philipp Moritz (C. P. Moritz), German essayist and travel writer (born 1756)
July 4 – Antoine-Marin Lemierre, French dramatist and poet (born 1733)
November 3 – Olympe de Gouges, French dramatist and political activist (guillotined; born 1748)
November 17 – Louis Pierre Manuel, French essayist and politician (guillotined, born 1751)
December 22 – William Watkiss Lloyd, English polymath (born 1813) |
1793 in literature | References | References |
1793 in literature | Table of Content | Short description, Events, New books, Fiction, Drama, Poetry, Non-fiction, Births, Deaths, References |
1792 in literature | Short description |
This article contains information about the literary events and publications of 1792. |
1792 in literature | Events | Events
February 18 – Thomas Holcroft's the comedy The Road to Ruin is premièred at Covent Garden in London.
July – Molière's body is exhumed for reburial in the Museum of French Monuments in Paris, having been originally buried in the ground reserved for unbaptised infants, because actors were not allowed to be buried on sacred ground.
September 29 – The Theatre Royal, Dumfries, opens as The Theatre. By the 21st century this will be the oldest working theatre in Scotland.
unknown date – Henry Walton Smith and his wife Anna set up a newsagent's business in London that will become the bookselling chain WHSmith. |
1792 in literature | New books | New books |
1792 in literature | Fiction | Fiction
Hugh Henry Brackenridge – Modern Chivalry: containing the Adventures of Captain John Farrago and Teague O'Regan, his servant
Johann Baptist Durach – Philippine Welserin
Susannah Gunning – Anecdotes of the Delborough Family
Thomas Holcroft – Anna St. Ives
Cornelia Knight – Marcus Flaminius
Charlotte Palmer
It Is and It Is Not a Novel
Integrity and Content: an Allegory
Mary Robinson – Vancenza; or The Dangers of Credulity
Charlotte Turner Smith – Desmond |
1792 in literature | Children | Children
Elizabeth Pinchard – The Blind Child, or, Anecdotes of the Wyndham Family |
1792 in literature | Drama | Drama
Pierre Beaumarchais – La Mère coupable
Joseph Chénier – Caïus Gracchus
Leandro Fernández de Moratín – La comedia nueva
Thomas Holcroft – The Road to Ruin
Elizabeth Inchbald – Cross Partners
William Macready the Elder – The Irishman in London
Thomas Morton – Columbus |
1792 in literature | Poetry | Poetry
Samuel Rogers – The Pleasures of Memory, with Other Poems |
1792 in literature | Non-fiction | Non-fiction
Saul Ascher – Leviathan oder über Religion in Rücksicht des Judentums (Leviathan or religion in respect of Judaism)
Yuan Mei (袁枚) – Suiyuan shidan (Recipes from the Garden of Contentment)
Arthur Murphy – An Essay on the Life and Genius of Samuel Johnson
Maria Riddell – Voyage to the Madeira and Leeward and Caribbean Isles, with Sketches of the Natural History of these Islands
Gottlob Ernst Schulze – Aenesidemus
Mary Wollstonecraft – A Vindication of the Rights of Woman |
1792 in literature | Births | Births
February 10 – Frederick Marryat (Captain Marryat), English novelist and naval officer (died 1848)
April 5 – John Lavicount Anderdon, English writer (died 1874)
April 25 – John Keble, English poet (died 1866)
June 21 – Ferdinand Christian Baur, German theologian (died 1860)
July 2 – Thomas Phillipps, English book collector (died 1872)
August 4 – Percy Bysshe Shelley, English poet and radical (died 1822)
October 17 – Sir John Bowring, English political economist and miscellanist (died 1872)
October 20 – John Pascoe Fawkner, pioneer, newspaper publisher in Melbourne, Victoria, Australia (died 1869)
October 28 – Anne Knight (Anne Waspe), English children's writer and educationist (died 1860)
November 26 – Sarah Grimké, American abolitionist and suffragist (died 1873)
November 28 – Victor Cousin, French philosopher (died 1867)
December 18 – William Howitt, English historical writer and poet (died 1879) |
1792 in literature | Deaths | Deaths
April 23 – Karl Friedrich Bahrdt, German theologian and writer (born 1741)
May 4 – Giuseppe Garampi, Italian scholar and book collector (born 1725)
May 12 – Charles Simon Favart, French dramatist (born 1710)
May 29 – Thomas Marryat, English medical writer and physician (born 1730)
June 4
John Burgoyne, English dramatist and army officer (born 1723)
Jakob Michael Reinhold Lenz, Baltic German dramatist (born 1751) (found dead early this morning, May 24 in the Julian calendar)
September 25 – Jacques Cazotte, French novelist (born 1719) (executed)
September – John Edwards (1747–1792), Welsh poet (born 1747)
December 7 – Marie Jeanne Riccoboni (Laboras de Mezières), French novelist (born 1714) |
1792 in literature | References | References |
1792 in literature | External links | External links |
1792 in literature | Table of Content | Short description, Events, New books, Fiction, Children, Drama, Poetry, Non-fiction, Births, Deaths, References, External links |
Windsurfing | Short description | thumb|right|Windsurfing on Columbia River, Oregon.
Windsurfing is a wind-propelled water sport that is a combination of sailing and surfing. It is also referred to as "sailboarding" and "boardsailing", and emerged in the late 1960s from the Californian aerospace and surf culture. Windsurfing gained a popular following across Europe and North America by the late 1970s and had achieved significant global popularity by the 1980s. Windsurfing became an Olympic sport in 1984. |
Windsurfing | History | History
thumbnail|Darby sailboard, Popular Science, 1965
Newman Darby of Pennsylvania created a rudderless "sailboard" in 1964 that incorporated a pivoting"square rigged" or "kite rigged" sail which allowed the rider to steer a rectangular board by tilting the sail forward and back. Darby's design however had notable performance limitations. Unlike the modern windsurfer design, Darby's sailboard was operated "back winded", with the sailor's back to the lee side of a kite-shaped sail. This much less efficient and less desirable sailing position is opposite of how a modern windsurfer is operated.alt=Jim Drake's Windsurfer Blueprint|thumb|350x350px|Jim Drake's Windsurfer Blueprint
Jim Drake, a California aeronautical engineer, invented and patented a sail powered surfboard in 1967 that became the modern Windsurfer we know today. Drake's version differed from Darby's in many significant ways. The sailor stood upright on a large, high-performance surfboard while holding directly onto the windward side of an aerodynamically shaped triangular sail.
Peter Chilvers is also cited for inventing a kind of sailboard in England in 1958.
Drake has stated in various interviews that he recognizes Darby and Chilvers as early sailboard pioneers and sees himself as the sports "re-inventor". |
Windsurfing | Drake's first day | Drake's first day
On May 21, 1967, Jim Drake made history by successfully sailing the world's first modern sailboard.
The details of Jim Drake's original windsurfing concept were published in 1969 by Drake's employer at the time, the RAND Corporation, in a technical paper he wrote and presented titled, Windsurfing - A New Concept in Sailing."
Further details on the invention can be read in published interviews.
Despite forty years of subsequent development, Drake's original Windsurfer design is still remarkably similar to today's equipment, and the word "windsurfing" has become synonymous with the sport itself. |
Windsurfing | The sport's first company | The sport's first company
Drake's revolutionary sailing concept, caught the attention of one of Drake's friends, a businessman named Hoyle Schweitzer, who became interested in patenting and marketing Drake's new invention.
Jim Drake and Hoyle Schweitzer together started the sport's first company, Windsurfing International, in late 1968 out of Drake's Santa Monica, California home.
Windsurfing International registered the term "Windsurfer" as a trademark at the United States Patent and Trademark Office in 1970. Windsurfing International Inc. created a popular one-design racing class, which was influenced by the desire to provide a fleet of racers with a uniformly constructed "boat," so that rider skill, rather than equipment choice, would determine competitive results. The first Windsurfer Class World Championship regatta took place in San Diego, California in 1973. |
Windsurfing | Patent disputes | Patent disputes
On March 27, 1968, Jim Drake, an aeronautical engineer, and Hoyle Schweitzer, a businessman filed the very first windsurfing patent, which they were granted by the USPTO in 1970.
Through the seventies, and early eighties windsurfing was the fastest growing sport on earth. Schweitzer aggressively protected his patent around the world through Sub-licensing the rights to anyone who wanted to manufacture and sell sailboards. Windsurfing International's usurious royalty fee charges, which its competitors were forced to pay, were so high that many observers felt it needlessly limited the growth of the sport. Mr. Schweitzer claimed this was to promote his brand and the Windsurfer One Design racing class, but most believed it was so he could maximize his own profits. The sport underwent very rapid growth however, particularly in Europe after the sale of a sub-license sold to Ten Cate Sports in the Netherlands. In 1975 Ten Cate Sports sold 45,000 boards in Europe. |
Windsurfing | Equipment | Equipment
Windsurfing equipment has evolved in design over the years and are often classified as either shortboards or longboards. Longboards are usually longer than 3 meters, with a retractable daggerboard, and are optimized for lighter winds or course racing. Shortboards are less than 3 meters long and are designed for planing conditions.
While windsurfing is possible under a wide range of wind conditions, most intermediate and advanced recreational windsurfers prefer to sail in conditions that allow for consistent planing with multi-purpose, not overly specialized, free-ride equipment. Larger (100 to 140 liters) free-ride boards are capable of planing at wind speeds as low as if rigged with an adequate, well-tuned sail in the six to eight square meter range. The pursuit of planing in lower winds has driven the popularity of wider and shorter boards, with which planing is possible in wind as low as , if sails in the 10 to 12 square meter range are used.
Modern windsurfing boards can be classified into many categories: The original Windsurfer board had a body made out of polyethylene filled with PVC foam. Later, hollow glass-reinforced epoxy designs were used. Most boards produced today have an expanded polystyrene foam core reinforced with a composite sandwich shell, that can include carbon fiber, kevlar, or fiberglass in a matrix of epoxy and sometimes plywood and thermoplastics. Racing and wave boards are usually very light (5 to 7 kg), and are made out of carbon sandwich. Such boards are very stiff, and veneer is sometimes used to make them more shock-resistant. Boards aimed at the beginners are heavier (8 to 15 kg) and more robust, containing more fiberglass.
Beginner boards: (Sometimes called funboards) these often have a daggerboard, are almost as wide as Formula boards, and have plenty of volume, hence stability.
Freeride: Boards meant for comfortable recreational cruising (mostly straight-line sailing and occasional turning) at planing speed (aka blasting), mainly in flat waters or in light to moderate swell. They typically fall into the volume range of 90 to 170 liters. The so-called freeride sailing movement diverged from course racing as more recreational sailors chose to sail freely without being constrained to sailing on courses around buoys.
Racing longboards: Internationally recognised One Design Classes such as the WINDSURFER Class, Mistral One Design, or the old Olympic RS:X class race boards, and the new 2024 Olympic Class iQFoil.
Formula Windsurfing Class: Shorter boards up to one meter in width, for use in Formula Windsurfing races. See below for a more detailed description.right|thumb|Windsurfing in the late evening on a longboard at Sandbanks in the 1980s (Poole Harbour, England).
Slalom boards: In the past, the key feature of slalom boards was merely speed, but it has been proven that maneuverability and ease of use are as important as speed in order to get you around the slalom course faster, and therefore modern slalom boards are shortboards aimed at top speed, maneuverability and ease of use.
Speed boards: In essence an extremely narrow and sleek slalom board, built for top speed only.
Freestyle boards: Related to wave boards in terms of maneuverability, these are wider, higher volume boards geared specifically at performing acrobatic tricks (jumps, rotations, slides, flips and loops) on flat water. Usually 80 to 110 liters in volume, and about 203 to 230 centimeters in length, with widths frequently in excess of 60 centimeters. Freestyle boards began to diverge more noticeably in design from wave boards in the early part of the 2000 decade, as aerial tricks (the Vulcan, Spock, Grubby, Flaka, and related New School maneuvers, almost all involving a jump-and-spin component) became the predominant part of the freestyle repertoire, superseding Old School moves, in which the board did not leave contact with the water.
Wave boards: Smaller, lighter, more maneuverable boards for use in breaking waves. Characteristically, sailors on wave boards perform high jumps while sailing against waves, and they ride the face of a wave performing narrow linked turns (bottom turns, cutbacks, and top-turns) in a similar way to surfing. Wave boards usually have a volume between 65 and 105 liters, with a length between 215 and 235 centimeters, and 50 to 60 centimeters in width. A general rule is for a sailor to use a wave board whose volume in liters is about the same as the sailor's weight in kilograms – more volume providing additional flotation for sailing in light winds, and less for high winds, where less volume is needed to achieve planing. In recent years, the average width of wave boards has increased slightly, as the length has shrunk, while the range of volume has been maintained the same more or less—according to board designers this makes wave boards easier to use under a wider range of conditions by sailors of differing abilities. The most common sizes of sails used with wave boards are in the range of 3.4 to 6.0 square meters, depending on the wind speed and the weight of the sailor.
Sails
Modern windsurfing sails are often made of monofilm (clear polyester film), dacron (woven polyester) and mylar. Areas under high load may be reinforced with kevlar.
Two designs of a sail are predominant: camber induced and rotational. Cambered sails have 1–5 camber inducers - plastic devices at the ends of battens which cup against the mast. They help create a rigid aerofoil shape for faster speed and stability, but at the cost of maneuverability and how light the sail feels. The trend is that racier sails have camber inducers while wave sails and most recreational sails do not. The rigidity of the sail is also determined by a number of battens.
Beginners' sails often do not have battens, so they are lighter and easier to use in light winds. However, as the sailor improves, a battened sail will provide greater stability in stronger winds.
Rotational sails have battens which protrude beyond the back aspect of the mast. They flip or "rotate" to the other side of the mast when tacking or jibing, hence the rotation in the name. Rotational sails have an aerofoil shape on the leeward side when powered, but are nearly flat when sheeted out (unpowered). In comparison with cambered sails, rotational designs offer less power and stability when sailing straight, but are easier to handle when maneuvering. Rotational sails are usually lighter and easier to rig.
A windsurfing sail is tensioned at two points: at the tack (by downhaul), and at the clew (by outhaul). There is a set of pulleys for downhauling at the tack, and a grommet at the clew. Most shape is given to the sail by applying a very strong downhaul, which by design bends the mast. The outhaul tension is relatively weak, mostly providing leverage for controlling the sail's angle of attack.
The sail is tuned by adjusting the downhaul and the outhaul tension. Generally, a sail is trimmed more (flatter shape) for stronger winds. More downhaul tension loosens the upper part of the leech, allowing the top of the sail to twist and "spill" wind during gusts, shifting the center of effort (strictly, the center of pressure) down. Releasing downhaul tension shifts the center of effort up. More outhaul lowers the camber/draft, making the sail flatter and easier to control, but less powerful; less outhaul results in more draft, providing more low-end power, but usually limiting speed by increasing aerodynamic resistance.
The disciplines of windsurfing (wave, freestyle, freeride) require different sails. Wave sails are reinforced to survive the surf, and are nearly flat when depowered to allow riding waves. Freestyle sails are also flat when depowered, and have high low-end power to allow quick acceleration. Freeride sails are all-rounders that are comfortable to use and are meant for recreational windsurfing. Race sails provide speed at the expense of qualities like comfort or maneuverability.
The size of the sail is measured in square meters and can be from 3 m2 to 5.5 m2 for wave sails and 6 m2 to 15 m2 for race sails, with ranges for freestyle and freeride sails spanning somewhere between these extremes. Learning sails for children can be as small as 0.7 m2 and race sails up to 15 m2.
Associated Equipment
Mast
Boom
Fin (similar shape to a surfboard fin but is usually stronger for windsurfing)
Universal joint (elastic joints are more common, but some are mechanical)
Harness and Harness lines
Wet suit/dry suit
Footwear
Helmet
Personal flotation device
Travel gear – sail bags, board bags, car racks
Safety gear: line, distress strobe light, whistle, marine VHF radioWindsurfing Safety , San Francisco Boardsailing Association (SFBA) |
Windsurfing | Technique | Technique
A sailboard is powered and controlled by the coordinated movements of the sail about its uni-joint and of the sailor around the board. This is achieved by balancing the weight of the sailor against the wind pressure in the sail, while adjusting both factors relative to the board. Learning this involves the development of reflexes and "muscle memory" similar to the process of learning to ride a bicycle. These skills are typically and optimally done on large, buoyant boards in light winds on flat water. Depending on wind conditions and the skill or intentions of the rider, at some point the sailboard will begin planing, resulting in a rapid increase in speed. This higher speed requires the learning of new skills as the apparent wind changes and the board becomes steerable like a surfboard. |
Windsurfing | Learning and skill progression | Learning and skill progression
Learning is a strenuous activity with many falls into the water, climbs back onto the board and repeating. The time taken to reach the point of significant enjoyment varies greatly. |
Windsurfing | Youth | Youth
Windsurfing is suitable for children as young as 5, with several board and sail brands producing "Kids Rigs" to accommodate these short and light weight windsurfers. In some countries, organisations exist to provide entry into the sport in a semi-formal or club-style environment (i.e. The RYA's Team 15 scheme). Robert (Robby) Naish took up the fledgling sport of windsurfing at the age of 11, and in 1976 won his first overall World Championship title at the age of 13. |
Windsurfing | Light winds | Light winds
The board moves through the water – much like a sailing boat does – using an extendable centreboard (if available) and fin or skeg for stability and lateral resistance. The centreboard is retracted at broad points of sail, again similarly to a sailing boat, to allow for jibing control. In these conditions windsurf boards also tack and jibe like a sailing boat.
Directional control is achieved by moving the rig either forward (turning away from the wind) or aft (turning towards the wind). When jibing, the clew of the sail is let around and allowed to rotate out and around the mast.
Fall recovery: The rider climbs onto the board, grabs the pulling rope (uphaul), makes sure the mast foot is placed between his/her two feet, pulls the sail about one third out of the water, lets the wind turn the sail-board combination until he/she has the wind right in the back, pulls the sail all the way out, places the "mast hand" (hand closest to the mast) on the boom, pulls the mast over the center line of the board, places the "sail hand" (hand furthest from the mast) on the boom, then pulling on it to close the sail and power it. |
Windsurfing | Strong winds | Strong winds
right|thumb|Ideal sail size (m2) for different wind speeds and rider weights (recreational level). The red values indicate sail sizes that are unpractical or not available.
In planing conditions a harness is typically worn to more efficiently use the rider's weight to counter the force in the sail. As the wind increases, the rider continues to sheet the sail, the fin generates more lift, and the board gains speed, transitioning onto a plane. The volume of board in the water (displacement) decreases, and the rider moves rearward, stepping into the footstraps for improved control. When planing, the board skims on the surface rather than displacing water as it moves. Planing can be achieved at different wind speeds depending on the rider's weight, sail and fin size, wave conditions, and rider ability. With modern equipment planing can normally be achieved at a wind speed of around . The transition from displacement motion to planing requires a jump in energy, but once planing, water resistance decreases dramatically. This means that it is possible to continue to plane, although the wind has dropped below a level that would be required to transition to plane. A board in plane can be much smaller than a board moving by displacement (thereby gaining an advantage in gear weight and board control). Lateral resistance to the wind is provided by the fin alone (generating more lift at higher speeds) and a centreboard is no longer used (smaller boards do not have one). A fin generates lift, transferring a strong load to the board, and so is usually constructed of carbon fiber for accurate shape and strength. A low-pressure area develops on the windward side of the fin, which can lead to cavitation, leading to a sudden loss of lift, called "spin-out" (equivalent to "stalling" in flight terminology). Ideal planing conditions for most recreational riders is of wind, but experts can windsurf in much windier conditions. Planing is considered one of the most exhilarating aspects of the sport.
Steering is mainly achieved by changing the center of lateral resistance located along the daggerboard or fin through rotating the sail either fore and aft. Unlike fixed mast sail a boat, windsurfing is rudderless and uses the universal joint to allow steering the board with the sail alone. Jibing is done at full speed (a so-called "carve jibe", "power jibe" or "planing jibe"), whereby the rider turns downwind by leaning the sail forward, sheeting and applying pressure to the inside rail. Leaning into the turn much like a snowboarder making a toe-side turn. Pressure is released from the sail as the board turns downwind, allowing for the sail to be jibed. Tacking is turning around going upwind, and at higher speed has become an advanced maneuver, requiring quick movements and good balance. A heel-side turn while planing (called a "cut-back") is usually only executed in wave riding.
Water-start: In strong winds it is difficult to uphaul the sail (pulling it out of the water while standing on the board) so waterstarting is necessary. This is done (while water treading) by positioning the mast perpendicular to the wind, lifting the luff out of the water to allow the wind to catch the sail, and then having the sail pull the sailor onto the board. As the sail becomes powered, it is then trimmed to bring the rider, board, and sail back onto a plane. Occasionally a rider may be unable to waterstart if the wind has dropped. If this happens the rider can wait for a gust and "pump" the sail to get back on the board. If this becomes hopeless uphauling the sail will be necessary. |
Windsurfing | Racers | Racers |
Windsurfing | Long-board classes | Long-board classes |
Windsurfing | Olympic class | Olympic class
Olympic Sailing included Olympic Boardsailing as a demonstration Sport, this test event was sailed on the Windglider fun board at the Olympic Games of 1984. Olympic Boardsailing was given full Sport status with the Lechner at the 1988 Olympic Games. sailing events at the Summer Olympics A Women's Olympic Lechner 390 Boardsailing Class of Sailing was added the Summer of 1992.
The Olympic Games from 1896 did not include any women specific class of sailing until 1988. The Boardsailing Class officially began the year of 1988 with only a Men's Olympic Lechner Boardsailing Class. The Barcelona Games of 1992 was significant to the history of Women in Sport, when the Olympic Women's Boardsailing Class began in Spain on the Mediterranean Sea.*
The first three classes were: Windglider(demo), Division II(men only), Lechner A-390 (Women Class & Men's Class) and the Mistral One Design Class. The Mistral had a worldwide organization with Mistral Schools to learn windsurfing. This manufacturer had a range of boards from short boards, wave boards, slalom boards, fun boards and race boards.
The Summer of 1992 the Olympic Mistral One Design was selected as versatile for youth, women and men. This gear was particularly ideal for a broad wind range from five knots to thirty-five knots of wind.
Olympic Windsurfing involves 'One Design' boards, each sailor windsurfing with the identical board design, daggerboards, fins and sails. The equipment is specifically selected to allow racing in a wide range of sailing conditions. The former Mistral Olympic class was better for youth, women and light weight men. Many women changed classes of Olympic Sailing when the gear was changed from Mistral to RSX. The next class was favoured by middle weight and heavy weight men with the shift to a significantly larger sail size. The Neil Pryde RS:X was used for the first time in the 2008 Summer Olympics. In 2024 the new Olympic Class windsurfer used advanced foil technology with the iQFoil one design class. |
Windsurfing | One Design Racing classes | One Design Racing classes
These offer hugely popular class racing around the world thanks to relatively low cost, the same gear design is competitive for many years with no class changes. The pro gear in contrast has rapid design change as often as every six months, only with sponsorship is constant upgrading practical. The steady constant of the one design is fun for recreation, the introduction to competition that allows intermediate windsurfers to race on the same gear design as the best athletes from the Olympic Class. These one design classes are the most social of all racing classes. The most popular one design classes are: the original WINDSURFER class, the long running Mistral One Design, the Youth development class Bic-Techno and the rapidly expanding new iQFoil. |
Windsurfing | Formula class | Formula class
right|thumb|Formula racer in San Francisco Bay.
Formula windsurfing has developed over the last 15 years in order to facilitate high-performance competition in light and moderate winds. Formula is now a class of windsurfing boards controlled by World Sailing that has the principal characteristic of a maximum 1m width. They have a single fin of maximum length 70 cm and carry sails up to 12.5 m2. Class rules allow sailors to choose boards produced by multiple manufacturers, as long as they are certified as Formula boards and registered with ISAF, and use fins and sails of different sizes. With the sail, fin and board choices, the equipment is able to be tailored to suit sailors of all body shapes and formula windsurfing presents one of the fastest course-racing sailing craft on the water. Formula Windsurfing is popular in many locations around the globe with predominantly light winds and flat water.
Large sails in combination with the 'wide-style' design allow planing in very low wind conditions as well as control and usability in high winds and bigger sea conditions. Non-planing sailing is very difficult with this design and racing is only conducted with a strict wind minimum in place. Formula boards are used on "flat water" as opposed to coastal surf, but racing is still held in windy conditions involving swell and chop. In 2008, a Formula Windsurfing Grand-Prix World Tour began, with events in Europe and South America complementing the single-event World Championships as a professional tour for the Formula class.
Formula boards have excellent upwind and downwind ability, but are not as comfortable on a beam reach unless fin sizes are reduced. This explains why the course is usually a box with longer upwind and downwind legs, or just a simple upwind-downwind return course. |
Windsurfing | Raceboard class | Raceboard class
Raceboards are longer windsurf boards with a daggerboard and movable mast rail allowing the sailor to be efficient on all points of sail. Excellent upwind ability is combined with good reaching and even downwind ability typically sailed in an Olympic triangle course. Whilst in decline in manufacture since the advent of shortboard course racing (which evolved into Formula) there remains some models in production and most notably the IMCO One Design remains popular amongst amateur racing clubs. |
Windsurfing | Short-board classes | Short-board classes |
Windsurfing | Slalom | Slalom
Slalom is a high-speed race. Typically there are two sorts of slalom courses.
Figure of eight: All of the course should on a beam reach with two floating marks that have to be jibed around.
Downwind: More than two marks are laid and sailors sail a downwind course – jibing around each mark only once.
Slalom boards are small and narrow, and require high winds. Funboard class racing rules require winds of for the slalom event to take place. |
Windsurfing | Ocean Slalom Marathon | Ocean Slalom Marathon
There are 3 major Ocean Slalom Marathons in the world: The Defi-Wind in France, The Lancelin Ocean Classic in Western Australia, and the Hatteras Marathon in the USA. |
Windsurfing | Super X | Super X
This discipline is a cross between freestyle and slalom. Competitors race on a short downwind slalom course, must duck jibe on all turns, and are required to perform several tricks along the way. Competitors are required to wear protective equipment. The Super X discipline was short lived and is now largely unpracticed; it reached its peak in the early 2000s, |
Windsurfing | Speedsailing | Speedsailing
Speedsailing takes place in several forms. The International Speed Windsurfing Class (ISWC) organizes (under the umbrella of World Sailing) competitions in various locations around the world known for conditions suitable for good speeds. The events are made up of heats sailed on a 500m course. The average of each sailor's best 2 speeds on the 500m course, which is typically open for 2 hours per heat, is their speed for that heat. As such it is possible for the sailor with the outright fastest time not to win the heat if his second best time pulls his average down. Points are given for the placings in the heats and the overall event winner is the sailor with the best point score (again not necessarily the fastest sailor). Likewise points are given for places in the events and at the last event a World Speedsurfing Champion is crowned.
On record attempts controlled by the World Sailing Speed Record Council (WSSRC) competitors complete timed runs on a 500m or 1 nautical mile (1,852m) course. The current 500m record (for Windsurfers) is held by French windsurfer Antoine Albeau. The women's 500m Record is 48.03 knots held by Jenna Gibson, from England, also in Luderitz. The Men's nautical mile record is held by Bjorn Dunkerbeck and the women's mile record is held by Zara Davis both set in Walvis Bay, Namibia
With the advent of cheap and small GPS units and the website www.gps-speedsurfing.com, Speedsurfers have been able to organise impromptu competitions amongst themselves as well as more formal competitions such as the European Speed Meetings and Speedweeks/fortnights in Australia. With over 5000 sailors registered it is possible for windsurfers all over the world to compare speeds.
Men's Speed Sailing RecordsDateSailorLocation1 December 2024Antoine AlbeauLuderitz, Namibia5 November 2015Antoine AlbeauLuderitz, NamibiaNovember 2012Antoine AlbeauLuderitz, Namibia
Women's Speed Sailing RecordsDateSailorLocation25 November 2024Jenna GibsonLuderitz, Namibia25 November 2022Heidi UlrichLuderitz, NamibiaNovember 2017Zara DavisLuderitz, Namibia |
Windsurfing | Indoor | Indoor
"In 1990 indoor windsurfing was born with the Palais Omnisports de Paris – Bercy making its spectacular debut. It was during this first indoor event that Britain's Nik Baker, from the south coast, flourished and went on to add a whopping x6 Indoor World Championships to his name".
Indoor windsurfing competitions are held, especially in Europe, during winter. Powerful fans lined up along the side of a large pool, propel the windsurfers. Indoor competition disciplines include slalom style races and ramp jumping competitions.Archived at Ghostarchive and the Wayback Machine: It is extremely dangerous because the pool is barely one meter deep and is surrounded by concrete.
World Champion Jessica Crisp has had arguably the worst injury in the history of the indoor events when, during a warm up session jumping the ramp, she snapped her leg and had to have emergency surgery in a French hospital. This was at the height of her professional career and fame across Europe.
The most famous indoor champions include Robert Teriitehau, Jessica Crisp, Robby Naish, Nick Baker, Eric Thieme, and Nathalie LeLievre. |
Windsurfing | Riders | Riders |
Windsurfing | Wavesailing | Wavesailing
Wave sailing took off during the rapid development of windsurfing on the Hawaiian islands of Oahu and Maui. It can be seen as comprising two distinct (but related) parts, wave riding and wave jumping.
A typical wave contest will score two jumps going out and two wave rides coming in. A high scoring heat would consist of a double clean forward rotating jump, a high one foot backward rotating jump, a long wave ride with flowing bottom turns, radical top turns, a series of aerials and a 360 aerial manoeuvre on the face of the waves such as a 'goiter', 'taka', wave 360, planing forward or clean flowing back-loop. Depending on the conditions at the location, some competitions will focus more on jumping while others focus more on the wave-riding aspects.
The most famous wave riding locations on earth include: Ho'okipa on the north shore of Maui, Diamond Head on Oahu, Klitmøller in Denmark, Pozo and Tenerife in the Canary Islands, Cabo Verde off the north west coast of Africa, Moulay in Morocco, Margaret River in Western Australia, Pacasmayo in Peru, Topocalma in Chile, and Omaezaki in Japan.
The PWA World Cup Wavesailing competitions crown the professional world champions each year. One of the most prestigious events in the windsurfing world is called The Aloha Classic at Ho'okipa Beach on the north shore of Maui, Hawaii.
The Aloha Classic held at Ho'okipa Beach Park on the north shore of Maui, takes place each year in late October and early November for the best wind and wave conditions and it is common to have 15–20 foot wave faces during the contest. Since 2011 the event has been run by the International Windsurfing Tour (IWT)[3] as the Grand Final of the IWT Wave Tour. The IWT is the Hawaiian-based organisation for the wave riders of the Asia Pacific hemisphere. The Aloha Classic has often been the final event of the Professional Windsurfers Association (PWA)[4] crowning the PWA Wave World Champions. |
Windsurfing | Wave riding | Wave riding
Wave riding is a form of surfing with the extra speed and power afforded by the sail. It is strongly connected to its roots in surfing in style and culture. It involves the rider performing a series of bottom turns, top turns, and cutbacks whilst riding an unbroken wave back to the shore. Top wave sailors are able to incorporate aerial moves into their wave riding and will use overhanging wave lips to launch themselves out in front of the wave in spectacular giant aerials. |
Windsurfing | Wave jumping | Wave jumping
Wave jumping involves stunts of varying levels of difficulty which are performed after the rider has jumped from the peak of an unbroken wave. These are commonly referred to as aerial moves and include both forward rotation and backward rotations. The rider and his equipment rotate, doing single and double rotations and jumps where the sailor contorts his or her body and equipment. Recent innovations have included combining moves whilst airborne and, for the first time in 2008, one professional sailor, Ricardo Campello, has made attempts at a triple forward loop during a 2008 PWA competition. |
Windsurfing | Big wave riding | Big wave riding
At the most extreme end of the sport is big wave riding which means riders on waves faces over 30 feet high. The most popular place for this is on the north shore of Maui at place called Pe'ahi to the local Hawaiians, and known as JAWS to the rest of the world. The biggest waves here can be up to 60 foot faces. It breaks only in the winter months from late October to March. Other famous big wave locations include Nazaré in Portugal. Famous contemporary big wave riders include Kai Lenny, Marcilio Browne, Robby Swift, Sarah Hauser, Jason Polakow, and Robby Naish. The inaugural Big Wave Challenge announced the first ever winners in this category on April 10, 2020. |
Windsurfing | Storm riding | Storm riding
The most famous storm riding event is known as The Red Bull Storm Chase. It occurs only when there is a massive storm forecast with winds over 60 knots and giant waves over 20 feet. It is an invitational event and is extremely dangerous. The most recent winner was West Australian Jaeger Stone. |
Windsurfing | Freestyle | Freestyle
Freestyle is a timed event which is judged. The competitor who has the greatest repertoire, or manages to complete most stunts, wins. Freestyle is about show and competitors are judged on their creativity. Both the difficulty and the number of tricks make up the final score. Sailors who perform tricks on both tacks (port and starboard), and perform the tricks fully planing score higher marks. High scoring moves include Shifty (Shaka Pushloop), Double Air-Culo, Air-Kabikuchi, Air-Skopu and double Power-Moves, for example Air-Funnel Burner and Double Culo. The latest freestyle windsurfing is well documented and gets constantly updated on Continentseven. For novice windsurfers, low-wind freestyle tricks are an appropriate start, such as sailing backwards with the fin out of the water, or transitioning from a sailing stance to sitting on the board while continuing to sail. |
Windsurfing | Big air | Big air
Competitors compete to see who can record the highest jump or maneuver. A 3D accelerometer is worn to measure and record heights of the jumps. Xensr is a manufacturer of 3D accelerometers and promoter of the Big Air competition. It is a popular discipline on the Columbia River near the town of Hood River, Oregon, USA. |
Windsurfing | International stars | International stars |
Windsurfing | Top men | Top men
Robby Naish (USA): one of the first windsurfing champions to gain international fame, he dominated the early years of competition in the 1970s and 1980s. World Champion from 1976 to 1979, Overall World Champion from 1983 to 1987, and Wave World Champion in 1988, 1989, and 1991. IWT BIG WAVE All-Time BIGGEST WAVE RIDER Champion 2020 (photo)
Björn Dunkerbeck (ESP): the successor to Naish, he dominated international professional competition from the late 1980s and throughout the 1990s. Twelve-time PWA Overall World Champion in a row. He won the Professional Windsurfers Association (PWA) World Championships for Slalom, Wave, Course Racing and Overall, a record forty one times in total. He is credited in the Guinness Book of World Records as the most successful athlete of all time with 42 World Titles.
Antoine Albeau (FRA): 22 times World Champion in various disciplines: Formula windsurfing, Super X, Freestyle, Slalom, Race, Speed, Overall. Holder of the windsurf speed record 53.27 knots, on the 5th of November 2015.
Stephan van den Berg (NED), World Champion 1979–1983, gold medal winner first Olympic windsurfing contest in Los Angeles, California in 1984.
Anders Bringdal (SWE). Division 2 Heavyweight Champion 1984, Funboard World Champion 1985, Professional windsurfer PBA/PWA 1985 at Sylt. PBA Slalom Champion 1987, PBA Courseracing Champion 1988, Speed World Cup Champion 2009. First man over 50 knots in official timing over 500 metres in Lüderitz 2012.
Arnaud de Rosnay (FRA): Photographer, and windsurfing adventurer. Best known for his open-ocean windsurfing exploits, and numerous long distance crossings in conflict areas. Lost at sea in November 1984 in the Taiwan Strait. He created the first speedsailing event in 1981, a 40 km race in Maui. 80 competitors participated in the first event, Arnaud de Rosnay finishing second behind Robby Naish. He is also credited with the invention of Kite surfing (1980) and land sailing (Speedsail 1977), even crossing a distance of 1380 km in the Sahara in 1979.
Christian Marty (FRA): Airline pilot for Air France. He was the first person to windsurf across the Atlantic Ocean in 1981, from Dakar, Senegal to Kourou, French Guiana. He was later captain of Air France Flight 4590 which crashed after takeoff killing everyone on board and several more people on the ground.
Peter Boyd (USA): Moved to Maui in 1980, and pioneered several windsurfing maneuvers. He was the first to perform an aerial loop, which was considered impossible by many. The maneuver opened the door to a variety of aerial loop variations, including the push loop and double rotations. While innovation was his main focus, Boyd did defeat World champion, Ken Winner several times at International competitions.
Guy Cribb (GBR): four times world championships runner-up in the 1990s. 13 UK champion titles.
Mark Angulo (USA): Early pioneer of many wave sailing moves, including the wave-face 360.
Jason Polakow (AUS): PWA Wave World Champion, 1997, 1998. First windsurfer to ride big wave of Nazare, in Portugal.
Kevin Pritchard (USA): PWA Overall World Champion, 2000. PWA Wave World Champion, 2006. Aloha Classic Wave Champion 2016.
Nik Baker (GBR): Three-time PWA Wave World 2nd Place, six-time Indoor World Champion.
Josh Angulo (USA): Mark's younger brother and early pioneer of Cape Verde.
Tonky Frans (BON): 3rd world freestyle 2009. 1st Midwinters Merit Island Freestyle Competition in 2001.
Jean-Patrick van der Wolde (NED): IFCA Junior World Champion of 2011.
Mike Waltz (USA): first to put a windsurfing sail on a surfboard and sail the famed Hookipa beach on Maui in 1979. This shifted the entire sport from the original long boards to the shorter boards ridden today. Mike also hosted Maui's first professional wave sailing and slalom event in 1981, which became the foundation of the windsurfing world tour, and Maui became the mecca for the sport both as a design center and a training ground for professionals.
Dave Kalama (USA): Although known for his big wave surfing and stand-up surfing accomplishments, he is an outstanding windsurfer and invented the move known as the Goiter.
Matt Schweitzer(USA): First World Champion (1974), and winner of 18 World Championship level events in subsequent years.
Josh Stone (USA): freestyle pioneer, inventor of the Spock, PWA Freestyle World Champion in 1999, 2000.
Ricardo Campello (VEN): a freestyle innovator, he created many difficult moves, PWA Freestyle World Champion in 2003, 2004, and 2005.
Kauli Seadi (BRA): pioneered freestyle maneuvers in wave competition. Ranked first in PWA Wave competition in 2005, 2007, 2008.
Gollito Estredo (VEN): 9 time PWA Freestyle World Champion 2005, 2006, 2008, 2009, 2010, 2014, 2015, 2017, 2018, innovator of many new freestyle tricks.
Thomas Traversa (FRA): PWA Wave World Champion 2014, 1st RedBull Storm Chase.
Steven van Broeckhoven(NED): European Freestyle Champion 2010, PWA Freestyle World Champion 2011.
Philip Köster (GER): 5 x Wave World Champion 2011, 2012, 2015, 2017, 2019.
Víctor Fernández (ESP): Wave World Champion 2010, 2016, and 2018.
Marcilio Browne (BRA): 4 x Wave World Champion 2013, 2022, 2023, 2024, 2 x Aloha Classic Champion, IWT BIG WAVE Most Radical All Time Champion 2020, PWA Freestyle World Champion 2008.
Boujmaa Guilloul (MOR): 1st PWA event Hawaii Pro wave 2004, 2014 1st AWT Pro Fleet - Starboard Severne Aloha Classic, 9th PWA Starboard Severne Aloha Classic, 2010 ranked 20th overall PWA Wave, 2009 8th Cabo Verde Wave, 2008 ranked 19th overall PWA Wave, 2007 ranked 14th Wave, came 5th in Guincho. 1st Aloha Classic 2014, 2nd IWT Wave Overall Pro Men 2015, 1st IWT Wave Overall Pro Men 2016.
Camille Juban (GDE): IWT BIG WAVE All-Time BIGGEST WAVE RIDER Champion 2020 (video), 2 x Aloha Classic Champion 2011 and 2018. 3 time AWT overall Pro Men Wavesailing champion 2012, 2013 and 2015.
Bernd Roediger (USA): 2 x Aloha Classic Champion 2012 (youngest ever winner at 16 years old), 2013.
Frank Ervin: Formula windsurfing lightweight world champion.
Morgan Noireaux (USA): 3 x Aloha Classic Champion 2014, 2015, 2017. IWT overall Pro Men Wavesailing champion 2017.
Antoine Martin (GDE): 2 x Aloha Classic Champion 2019 & 2023, 2 x IWT Wave Champion 2018, 2019, French National Wave Champion 2019.
Robby Swift (GB) Competing internationally in the PWA World Tour as a wave/freestyle sailor. He was the Youth World Champion, in Racing and Slalom 2000. |
Windsurfing | Top women | Top women
Jill Boyer (USA): World Wave Champion 1984.
Julie de Werd (USA): World Wave Champion 1984.
Clare Seeger (GBR): One of the top female windsurfers in the 1980s. She was also No 1 British Champion for 10yrs and was the first Briton to obtain and overall World Title. Clare won numerous events around the World until finally settling in Hawaii. She was one of the first women who did forward loops, push loops and was the first person to do a double back loop at Ho'okipa,Maui, Hawaii.
Lisa Penfield (USA): Freestyle World Champion 1985, multiple Championships from 1981– 1986.
Dana Dawes (USA): World Wave Champion 1986, 1987.
Natalie Siebel (GER): World Wave Champion 1986, 1988, 1990, 1992, 1994.
Angela Cocheran (USA): World Wave Champion 1989, 1991.
Natalie Lelievre (FRA): overall World Champion, 1984, 1985. World Wave Champion 1995, 1996, 1997.
Barbara Kendall (NZ): 3 time Olympian representing New Zealand with Gold in Barcelona 1992, Silver in Atlanta 1996, Bronze in Sydney 2000.
Jessica Crisp (AUS): 5 time Olympian representing Australia. PWA Overall World Champion 1994. PWA World Wavesailing Champion 1993.
Karin Jaggi (SUI): multiple PWA World Champion in freestyle, wave, speed competition, 1990s and 2000s. World Wave Champion 1998.
Daida Ruano Moreno (ESP): PWA Wave World Champion, 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009, 2010, 2011, 2013. Freestyle World Champion 2003–2006. The Most dominant female athlete in the history of wavesailing.
Iballa Ruano Moreno (ESP): PWA Wave World Champion, 1999, 2006, 2007, 2012, 2014, 2015, 2016, 2017, 2018. Twin sister of Daida Moreno.
Sarah-Quita Offringa (ARU): 25-time World Champion (15 Freestyle, 5 Slalom, 4 Wave & 1 Slalom-X), 3 x Aloha Classic Wave Champion 2016, 2019, 2023.
Sarah Hauser (NCL): IWT BIG WAVE All-Time BIGGEST WAVE RIDER Champion 2020 (photo), 3 x Aloha Classic Wave Champion 2017, 2018, 2024, 3 x IWT Wave Champion 2015, 2016, 2018.
Jenna Gibson (GBR): Women's Speed World Record Holder (48.03 knots over 500m). First woman to go over 50 knots peak speed. 4 x IFCA Slalom World Champion. |
Windsurfing | In popular culture | In popular culture
Due to the popularity of the sport in the 1970s, a song "Windsurfin'" was written by publisher Willem van Kooten and producer Jaap Eggermont. It sold over 200,000 copies and made it to no. 2 in the Netherlands in 1978. It was also a hit in Belgium and Germany.Surfer Today - The day The Surfers encouraged you to go 'Windsurfin''Dutch Charts - The Surfers - Windsurfin' |
Windsurfing | Related water sports | Related water sports
Other watersport variants using a board and wind power include Kiteboarding and Wingsurfing.
Kiteboarding uses a large kite (around 9 to 20qsm) on 20+m lines for wind power. Due to the strong possible upward lift, smaller boards with no significant buoyancy are used.
Wingsurfing or wing foiling uses a hand-held wing, a smaller version of a kite, to replace the sail. To offset the low wind power resulting from the comparatively small wing size (around 3 to 9 sqm), a Foilboard can be used.
Windfoiling mounts in the fin box a hydrofoil which lifts the board off the water and improves speeds due to reduced drag. |
Windsurfing | See also | See also
Kite ice skating — ice skater propelled by kite
Land sailing — yacht with wheels
Land windsurfing — on large skateboard, propelled by sail
Wakeboarding — water skiing on a board instead of skis
Waterskiing |
Windsurfing | References | References |
Windsurfing | External links | External links
Official Formula Class Website
Continentseven, international windsurfing website
WindsurfingMag Windsurfing Magazine
FollowTheWinds, international windsurfing news website
International Windsurfing Association
Category:American inventions
Category:Sailboat types
Category:Surfing
Category:Boardsports
Category:Articles containing video clips |
Windsurfing | Table of Content | Short description, History, Drake's first day, The sport's first company, Patent disputes, Equipment, Technique, Learning and skill progression, Youth, Light winds, Strong winds, Racers, Long-board classes, Olympic class, One Design Racing classes, Formula class, Raceboard class, Short-board classes, Slalom, Ocean Slalom Marathon, Super X, Speedsailing, Indoor, Riders, Wavesailing, Wave riding, Wave jumping, Big wave riding, Storm riding, Freestyle, Big air, International stars, Top men, Top women, In popular culture, Related water sports, See also, References, External links |
Multivalued function | Short description | thumb|Multivalued function {1,2,3} → {a,b,c,d}.
In mathematics, a multivalued function, multiple-valued function, many-valued function, or multifunction, is a function that has two or more values in its range for at least one point in its domain. It is a set-valued function with additional properties depending on context; some authors do not distinguish between set-valued functions and multifunctions, but English Wikipedia currently does, having a separate article for each.
A multivalued function of sets f : X → Y is a subset
Write f(x) for the set of those y ∈ Y with (x,y) ∈ Γf. If f is an ordinary function, it is a multivalued function by taking its graph
They are called single-valued functions to distinguish them. |
Multivalued function | Distinction from set-valued relations | Distinction from set-valued relations
thumb|right|upright=1.8|Illustration distinguishing multivalued functions from set-valued relations according to the criterion in page 29 of New Developments in Contact Problems by Wriggers and Panatiotopoulos (2014).
Although other authors may distinguish them differently (or not at all), Wriggers and Panatiotopoulos (2014) distinguish multivalued functions from set-valued relations (also called set-valued functions) by the fact that multivalued functions only take multiple values at finitely (or denumerably) many points, and otherwise behave like a function. Geometrically, this means that the graph of a multivalued function is necessarily a line of zero area that doesn't loop, while the graph of a set-valued relation may contain solid filled areas or loops. |
Multivalued function | Motivation | Motivation
The term multivalued function originated in complex analysis, from analytic continuation. It often occurs that one knows the value of a complex analytic function in some neighbourhood of a point . This is the case for functions defined by the implicit function theorem or by a Taylor series around . In such a situation, one may extend the domain of the single-valued function along curves in the complex plane starting at . In doing so, one finds that the value of the extended function at a point depends on the chosen curve from to ; since none of the new values is more natural than the others, all of them are incorporated into a multivalued function.
For example, let be the usual square root function on positive real numbers. One may extend its domain to a neighbourhood of in the complex plane, and then further along curves starting at , so that the values along a given curve vary continuously from . Extending to negative real numbers, one gets two opposite values for the square root—for example for —depending on whether the domain has been extended through the upper or the lower half of the complex plane. This phenomenon is very frequent, occurring for th roots, logarithms, and inverse trigonometric functions.
To define a single-valued function from a complex multivalued function, one may distinguish one of the multiple values as the principal value, producing a single-valued function on the whole plane which is discontinuous along certain boundary curves. Alternatively, dealing with the multivalued function allows having something that is everywhere continuous, at the cost of possible value changes when one follows a closed path (monodromy). These problems are resolved in the theory of Riemann surfaces: to consider a multivalued function as an ordinary function without discarding any values, one multiplies the domain into a many-layered covering space, a manifold which is the Riemann surface associated to . |
Multivalued function | Inverses of functions | Inverses of functions
If f : X → Y is an ordinary function, then its inverse is the multivalued function
defined as Γf, viewed as a subset of X × Y. When f is a differentiable function between manifolds, the inverse function theorem gives conditions for this to be single-valued locally in X.
For example, the complex logarithm log(z) is the multivalued inverse of the exponential function ez : C → C×, with graph
It is not single valued, given a single w with w = log(z), we have
Given any holomorphic function on an open subset of the complex plane C, its analytic continuation is always a multivalued function. |
Multivalued function | Concrete examples | Concrete examples
Every real number greater than zero has two real square roots, so that square root may be considered a multivalued function. For example, we may write ; although zero has only one square root, .
Each nonzero complex number has two square roots, three cube roots, and in general n nth roots. The only nth root of 0 is 0.
The complex logarithm function is multiple-valued. The values assumed by for real numbers and are for all integers .
Inverse trigonometric functions are multiple-valued because trigonometric functions are periodic. We have As a consequence, arctan(1) is intuitively related to several values: /4, 5/4, −3/4, and so on. We can treat arctan as a single-valued function by restricting the domain of tan x to – a domain over which tan x is monotonically increasing. Thus, the range of arctan(x) becomes . These values from a restricted domain are called principal values.
The antiderivative can be considered as a multivalued function. The antiderivative of a function is the set of functions whose derivative is that function. The constant of integration follows from the fact that the derivative of a constant function is 0.
Inverse hyperbolic functions over the complex domain are multiple-valued because hyperbolic functions are periodic along the imaginary axis. Over the reals, they are single-valued, except for arcosh and arsech.
These are all examples of multivalued functions that come about from non-injective functions. Since the original functions do not preserve all the information of their inputs, they are not reversible. Often, the restriction of a multivalued function is a partial inverse of the original function. |
Multivalued function | Branch points | Branch points
Multivalued functions of a complex variable have branch points. For example, for the nth root and logarithm functions, 0 is a branch point; for the arctangent function, the imaginary units i and −i are branch points. Using the branch points, these functions may be redefined to be single-valued functions, by restricting the range. A suitable interval may be found through use of a branch cut, a kind of curve that connects pairs of branch points, thus reducing the multilayered Riemann surface of the function to a single layer. As in the case with real functions, the restricted range may be called the principal branch of the function. |
Multivalued function | Applications | Applications
In physics, multivalued functions play an increasingly important role. They form the mathematical basis for Dirac's magnetic monopoles, for the theory of defects in crystals and the resulting plasticity of materials, for vortices in superfluids and superconductors, and for phase transitions in these systems, for instance melting and quark confinement. They are the origin of gauge field structures in many branches of physics. |
Multivalued function | See also | See also
Relation (mathematics)
Function (mathematics)
Binary relation
Set-valued function |
Multivalued function | Further reading | Further reading
H. Kleinert, Multivalued Fields in Condensed Matter, Electrodynamics, and Gravitation, World Scientific (Singapore, 2008) (also available online)
H. Kleinert, Gauge Fields in Condensed Matter, Vol. I: Superflow and Vortex Lines, 1–742, Vol. II: Stresses and Defects, 743–1456, World Scientific, Singapore, 1989 (also available online: Vol. I and Vol. II) |
Multivalued function | References | References
Category:Functions and mappings |
Multivalued function | Table of Content | Short description, Distinction from set-valued relations, Motivation, Inverses of functions, Concrete examples, Branch points, Applications, See also, Further reading, References |
American Physical Society | Short description | The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of knowledge of physics. It publishes more than a dozen scientific journals, including the prestigious Physical Review and Physical Review Letters, and organizes more than twenty science meetings each year. It is a member society of the American Institute of Physics. Since January 2021, it is led by chief executive officer Jonathan Bagger. |
American Physical Society | History | History
The American Physical Society was founded on May 20, 1899, when thirty-six physicists gathered at Columbia University for that purpose. They proclaimed the mission of the new Society to be "to advance and diffuse the knowledge of physics", and in one way or another the APS has been at that task ever since. In the early years, virtually the sole activity of the APS was to hold scientific meetings, initially four per year. In 1913, the APS took over the operation of the Physical Review, which had been founded in 1893 at Cornell University, and journal publication became its second major activity. The Physical Review was followed by Reviews of Modern Physics in 1929 and by Physical Review Letters in 1958. Over the years, Phys. Rev. has subdivided into five separate sections as the fields of physics proliferated and the number of submissions grew.
In more recent years, the activities of the society have broadened considerably. Stimulated by the increase in federal funding in the period after the Second World War, and even more by the increased public involvement of scientists in the 1960s, the APS is active in public and governmental affairs, and in the international physics community. It also conducts extensive programs in education, science outreach (specifically physics outreach), and media relations. Fourteen divisions and eleven topical groups covering all areas of physics research. Six forums reflect the interests of its fifty thousand members in broader issues, and nine sections organized by geographical region.
In 1999, APS Physics celebrated its centennial with the biggest-ever physics meeting in Atlanta. In 2005, APS took the lead role in United States participation in the World Year of Physics, initiating several programs to broadly publicize physics during the 100th anniversary of Albert Einstein's annus mirabilis. Einstein@Home, one of the projects APS initiated during World Year of Physics, is an ongoing and popular distributed computing project. |
American Physical Society | Name confusion and change proposal | Name confusion and change proposal
During the summer of 2005, the society conducted an electronic poll, in which the majority of APS members preferred the name American Physics Society. The poll became the motivation for a proposal of a name change promised in the leadership election that year. For legal reasons, the planned name change was eventually abandoned by the APS Executive Board.
To promote public recognition of APS as a physics society, while retaining the name American Physical Society, the APS Executive Board adopted a new logo incorporating the phrase "APS Physics."
APS introduced a new logo to replace the APS Physics logo on November 1, 2022. |
American Physical Society | Journals | Journals
The American Physical Society publishes 17 international research journals and an open-access online news and commentary website Physics.
Physical Review Letters (PRL): Letters; fundamental research in all fields of physics.
Physical Review X (PRX): Open access; pure, applied, and interdisciplinary physics.
PRX Energy (PRX Energy): Open access; advances in energy science and technology.
PRX Life (PRX Life): Open access; quantitative biological research.
PRX Quantum (PRX Quantum): Open access; advances in quantum information science and technology.
Reviews of Modern Physics (RMP): Reviews and Colloquia; Broad fundamental physics.
Physical Review A (PRA): Atomic, molecular, and optical physics.
Physical Review B (PRB): Condensed matter and materials physics.
Physical Review C (PRC): Nuclear physics.
Physical Review D (PRD): Particles, fields, gravitation, and cosmology.
Physical Review E (PRE): Statistical, nonlinear, and soft matter physics.
Physical Review Research (PRResearch): Open access; multidisciplinary.
Physical Review Accelerators and Beams (PRAB): Open access; accelerator science and technology.
Physical Review Applied (PRApplied): Experimental and theoretical applications of physics.
Physical Review Fluids (PRFluids): Fluid dynamics.
Physical Review Materials (PRMaterials): A broad-scope international journal for the multidisciplinary community engaged in research on materials.
Physical Review Physics Education Research (PRPER): Open access; experimental and theoretical research on physics education.
All members of APS receive the monthly publication Physics Today, published by the American Institute of Physics (AIP). |
American Physical Society | Units | Units
The American Physical Society has 47 units (divisions, forums, topical groups and sections) that represent the wide range of interests of the physics community. |
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